The concept of blending is old in the art with the art replete with various types of blenders for mixing solids or liquids. In one type of blending or mixing device paddles or agitators stir the contents of the hopper. Still other blending or mixing devices inject air into a chamber to agitate the contents of the chamber.
One type of flow mixing device for mixing solids such as dry granular materials is shown in my U.S. Pat. No. 4,944,958 wherein air is injected into a stream of dry granular materials to mix the granular materials as the mixed granular materials flows out a discharge port located at the bottom of the vessel.
Another type of device for flow mixing liquids is shown in U.S. Pat. No. 4,595,296 where as a liquid flows through a tank a bubble of air is periodically injected into the liquid at the bottom of the tank to mix the liquid as it flows through the tank and out a discharge port at the bottom of the tank.
Still another device for mixing fine grain material is shown in U.S. Pat. No. 3,097,828. In this device a plurality of nozzles are circumferentially spaced around a conical shaped head so that a gas under pressure can be directed thorough the fine grain material located in a cylindrical container. In this device, the contents of the container are churned upwards and mixed together through the sheer turbulence of the gas stream.
My U.S. Pat. No. 4,943,163 shows another type of blender for pneumatically mixing a batch of dry granular material. The invention includes a set of poppet valves that are circumferentially spaced around the bottom of the hopper with the poppet valves periodically injecting air under sufficient pressure so as to lift the batch of material off the bottom of the blender and then allow the material to drop to cause the materials to be blended together as the batch of material is repeatedly lifted and dropped.
U.S. Pat. No. 4,326,810 shows a mixing devices for powder materials where a set of nozzles are activated in a predetermined sequence to mix the powder material.
Another device for mixing granular particle materials is shown in U.S. Pat. No. 3,386,182 wherein the material in the container is fluidized by series of jets located at the bottom of the container with one of the jets having a higher velocity than the other jets.
The present invention comprises a hopper blender wherein granular or solid materials in the hopper are mixed or blended through periodic injection of a slug of fluid through a fluid port located at the bottom of the hopper. The fluid port is sealable through a slidable piston, which is cycled between a closed port condition and an open port condition. The slug of fluid is at sufficient energy so as to overcome the weight of a column of granular material located above the fluid port and at sufficient proximity to prevent backflow into the fluid port If the fluid is gas or which is lighter than the granular materials, the fluid flows upward allow the slug of gas to percolate upward through the granular materials to blend the materials in the hopper blender.